# Free Domain Security Checker

> Run a read-only outside-in domain security check across public hosts, DNS, HTTPS, TLS, email security, and baseline headers.

Canonical: https://sentryxmonitor.com/tools/domain-security-checker/
Last updated: 2026-08-08

Free read-only checker

A domain security checker combines several public observations to identify hosts, DNS and email policy, HTTPS and TLS state, baseline headers, and assets that may need ownership or monitoring review.

Only check domains you own or are authorized to assess. The scan is read-only and does not exploit systems.

## What does the check cover?

The Sentryx report uses public, unauthenticated evidence. It does not exploit applications, log in, fuzz inputs, access private data, or replace an authorized penetration test.

## Why check more than the main website?

Certificates, DNS, and public host discovery may reveal APIs, mail systems, staging names, and vendor services that are not linked from the homepage.

## What should happen after the check?

Confirm ownership, verify findings, close unnecessary exposure, assign remediation, and continuously monitor the assets that remain business-critical.

## What happens after you submit?

The focused checker opens the full Sentryx outside-in report for the submitted domain. The same public scan backend can show related DNS, TLS, host, email-security, and header evidence so a narrow check can lead to a more complete ownership and monitoring decision.

## Continue learning

- [External Attack Surface Management: A Practical Guide](https://sentryxmonitor.com/learn/external-attack-surface-management/) - Learn what EASM is, how external assets are discovered, how exposure changes, and how continuous monitoring supports an accurate internet-facing inventory.

- [Website Security Check](https://sentryxmonitor.com/services/website-security-check/) - Review scan scope and limitations.

- [Sample outside-in report](https://sentryxmonitor.com/report/?domain=example.com) - Related Sentryx Monitor guidance.

## Related
- [Home](https://sentryxmonitor.com/)